The invention relates to an anti-theft device for spectacle frames, comprising a housing which forms an opening to receive therein one bow of the spectacle frame, clamping means in the housing for fastening the housing to the bow, a rotatable operating member for the clamping means, which can be actuated only by using a special tool, the housing being dimensioned to allow, when fastening to the bow, the spectacle frame to be tried on and the bow to be folded, and an alarm element for affecting a magnetic, acoustic, or electromagnetic field.
An anti-theft device of this kind is shown and described in EP-B1-0 425 515. In the embodiments of the anti-theft device described therein the housing comprises an elongated socket to be mounted to the bow in a position projecting substantially perpendicularly therefrom, or in a position along the bow projecting in an oblique angle therefrom. The alarm element is mounted under a cover which is attached to the socket.
The prior art embodiments satisfy well the demands on connected with the anti-theft device, viz. unauthorized removal of the device from the projecting spectacle frame should not be possible and that the device may be left on the spectacle frame at try thereof as far as the majority of spectacle frames is concerned. There is, however, a tremendous variation of spectacle frames and as far as spectacle frames having xe2x80x9chighxe2x80x9d bows are concerned the anti-theft device cannot be fastened to the bow, and as far as tapering bows are concerned there is a risk that the anti-theft device can be withdrawn from the bow without untied the clamping means having been unified. Although the anti-theft device does not interfere with the try it may be an obstacle when exposing the spectacle frame in certain types of exposure racks, which limits the possibility of choosing a desired type of exposure.
The purpose of the invention is to provide an anti-theft device of the kind referred to above which overcomes said drawbacks and moreover can be manufactured in a simple way and therefore cheaper than the embodiments described in EP-B1-0 425 415.
For said purpose the anti-theft device according to the invention has been given the characterizing features of claim 1.
In order to more clearly explain the invention it will be described below with reference to the accompanying drawings in which
FIG. 1 is an end view of the housing forming part of the anti-theft device, as seen from the side where the operating member for the clamping means is accessible to be manipulated by means of a special tool,
FIG. 2 is a plan view of the anti-theft device,
FIG. 3 is a side view of the anti-theft device,
FIG. 4 is a cross-sectional view taken along line IVxe2x80x94IV in FIG. 1,
FIG. 5 is a cross-sectional view taken along line Vxe2x80x94V in FIG. 2 and discloses the anti-theft device in an opened position,
FIG. 6 is a corresponding cross-sectional view as FIG. 5 but discloses the anti-theft device in a closed position,
FIG. 7 is an end view and
FIG. 8 a plan view of the anti-theft device mounted on a bow which is partly indicated by dot-and-dash lines, and discloses an embodiment of the washer for the alarm element, forming part of the anti-theft device, and
FIGS. 9 and 10 are corresponding side views as in FIG. 7 but disclose two other embodiments of the washer.